Two-time Macau Grand Prix winner Dan Ticktum has lost his drive in Japan's Super Formula series, Autosport understands.
The 20-year-old Briton was placed in Super Formula with Team Mugen as a Red Bull Junior this season, but has scored just a single point from three races thanks to an eighth-place finish at Suzuka in the opening round.
The nadir came last weekend at Sugo - the scene of his strong SF debut in 2018 as a substitute for Nirei Fukuzumi, who was on Formula 2 duty at the time.
Ticktum qualified on the back row and finished a lapped 15th, while Mugen team-mate Tomoki Nojiri looked odds-on for a podium finish until he shot into the gravel while battling with Ticktum's fellow Red Bull Junior Lucas Auer.
By contrast, Auer has had a strong rookie season in Super Formula at the B-Max with Motopark squad - the Austrian finished third at Sugo to continue his progress after four years out of single-seaters competing in the DTM with Mercedes.
It has been suggested that IndyCar starlet and newly appointed Red Bull Junior Patricio O'Ward, who is making a one-off F2 debut with MP Motorsport at the Red Bull Ring this weekend, will take Ticktum's drive with Team Mugen for the remainder of the Super Formula season.
Sources close to Ticktum were unable to confirm or deny the story, and it is unclear whether the 2018 Formula 3 European Championship runner-up will continue to have a role on the junior programme of Red Bull, for which he also carries out simulator work for the F1 team.